Plastic distributed feedback laser biosensor

A wide variety of optical resonator structures have been used for label-free detection of chemical compounds, biomolecules, and cells, and several approaches have been developed commercially for application in life science research, environmental monitoring, quality control testing, and diagnostic testing. Label-free resonant optical sensors generally detect shifts in resonant wavelength or coupling angle caused by the interaction between the target molecule and the evanescent portion of resonant modes. Active resonator sensors, such as the distributed feedback laser (DFB) biosensor demonstrated in this work, have been drawing special interest because they generate their own narrow linewidth stimulated emission, while retaining simple light coupling instrumentation. Altering the refractive index (RI) of the media exposed to the DFB laser surface or surface adsorption of biomolecules changes the effective RI associated with the resonant mode, and results in modulation of the stimulated emission wavelength. The DFB laser sensor biosensor was fabricated with organic material on a flexible plastic substrate using a large surface-area nanoreplica molding process.